Method and apparatus for aerial propulsion



v De 2, 1924. 1,517,865

M. SCHIESARI METHOD AND APPARATUS FOR AERIAL PROPULSION Original Filed July 14, 1921 3 Sheets-Sheet 1 gmvemtoz 3 Sheets-Sheet '2 ina,

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1 Filed July 14 1921 g 2... .N......... 1 o a P Z v r o... ..H.". fi m J W /48 vwemtoi 3 7% M a 4 a D I w J W -00 3:... .N.. M y 5 M 9 7 5 m z 3 5 7 a a w Dec. 1924. 1,517,865

M. SCHI ESARI METHOD AND APPARATUS FOR AERIAL PROPULSION riginal ile July 1 1 1921 5 Sheets-Sheet g.

gvwemtoz MARIO'SCHIESARI, OF NEW YORK, N, Y.

METHOD AND APPARATUS FOR AERIAL PROPULSION.

Refiled for abandoned application Serial No. 484,827, filed .Tu1y 14, 1921. This application filled June 8,

' 1923. Serial No. 644,503.

drawings, forming a part of this specificatiOn.

This invention relates to afnovel method and apparatus for utilizing centrifugal force in order to produce propelling power 1. through the use of flexibly connected propellin elements; and its main object is to provide a novel method for utilizing centrifugal force whereby the propelling power of a flexibly connected propelling element rotating at a suitable speed may be exerted in an axial direction. 7

Another object of this invention is to provide a novel and improved form of propeller the action of which is based on the utilization of centrifugal force in order to create and maintain the necessary rigidity of the system so as to permit the transmission in an axial direction of the propelling power developed by flexibly connected rotating propelling elements, said form of propeller being especially suitable for'use in connection with flying machines.

A further object is to provide a novel and improved form of propeller having a variable radius of action so that a variable propelling power may be obtained by means of the same without changing its angular speed.

A still further object is to provide a novel 40 method whereby a lifting or I propelling force may be obtained through causing inclined surfaces connected to an axle by flexible retaining means, to travel in a circular path at asuflicient speed; said speed being comparable and equivalent for explanatory purposes to the speed at which the aerofoils of an ordinary aeroplane are caused to travel forward in order to cause an aeroplane to rise in the air; said speed being much lower than the circumferential speed of the propellers ordinarily used.

Another object of this invention is to provide a novel method for using centrifugal force whereby a flexibly connected rotating lifting element may be caused to travel in the air in a circular path and in an upwardly inclined position for signalling, advertising or ornamental purposes, such for instance as shown in a patent granted to me on April 3, 1923, entitled Apparatus for aerial projection, No. 1,450,- 263.

With these and other objects in view, as .Will more fully appear as the description proceeds, this invention furthermore consists in certain novel and improved conplanning; a very large percentage of the power delivered by the engine being lost because the screw fails to get a good hold on the air. Its moderate size, its. high velocity and the elastic nature of the medium in which it works constitute. the basic reasons for the screws handicap. The screwsends rearward a column of violently disturbed air .and sets uppronounced perturbations over a considerable area in the air ahead, moving, therefore, into a medium upon which its grip is discounted by the extent of the agitation. The hub and the massive inner sections of the blades do not doany helpful work so that a propeller of moderate diameter has only a limited volume of air to work upon.

On the other hand practical considerations impose a sharp limit to the length of ablade. It must be made of wood and loses strength rapidly'as itv becomes more and more attentuated; it can be made of no greater length than will fit into the general design of a plane, without increasing its height from the ground; and

strength for a high speed ratio cannot be provided as it can for the planes of the aeroplane by braces, wires and-struts.

It has been said that as the tip speed of a propeller approaches the velocity of sound, say 1100 feet per second, the usual air flow entirely breaks down, the slip most efl'ective.

stream rapidly diminishes and ultimately vanishes when the velocity of sound is reached; more recent experiments, however, have demonstrated that with carefully designed propellers the supposed physical limits at the velocity of sound do not exist, while the ratio of thrust to tip speed undergoes no appreciable variation in passing through that velocity. In theory, at least, the longer the blades, the less the width and the less the angle of incidence, the greater the etiiciency, but in practice, as stated before, there are sharp limitations in the construction of any aircraft propeller. On the other hand, to double the tract-ion of the airpropeller would more than double the life of the enginerunning it; proportionately increasing the relative velocity of the machine in the air and its load carrying capacity.

hile no usual propeller is expected to give more than ten pounds of thrust per unit of horse-power, propellers of aerofoil types, suggested in connection with the construction of helicopters, have yielded more than twenty pounds of thrust per unit of horsepower, said propellers making but 70 revolutions per minute and beingcarried by heavy rigid arms fifty feet long reinforced by eight steel wire ropes.

The present invention substantially aims to produce a form of propeller able to act upon the air much after the manner of aeroplane wings as the one that would be the The aerofoil surfaces meet the impinging air under the most favorable conditions and the reactions thus induced are in the main of a buoyant or lifting nature in eflect.

The vacuum created at the back of. an aeroplane wing is much the larger factor in the total lift impulse produced and advantage of this phenomenon may be taken in designing blades of an aeroform model, following paths where their impact with the air would be most efi'ective.

Said aerofoilsbeing placed at a distance from the hub, the use of that mass of material which characterizes the usual aeroplane screw, just where the speed of revolution is too low to produce a commensurate measure of thrust, is avoided.

As the description proceeds it will be more clearly seen that my propellers are in reality adaptations of aerofoil elements in combination with a rotating axle; being in fact constituted by miniature elastic, wings travelling in a predetermined circular path in the air, the cohesion and compressibility of which are fully taken into account. By means of a novel method of exploitation of centrifugal force, in combination with propelling or lifting power developed by aerofoils set at a certain angle of incidence, and moved through the air in a circular path, I

will show that it is possible to transmit in an. axial direction the propelling power developed by said rotating aerofoils, held by flexible cables, while through the wide use of opposing forces it is possible to obtain a series of dynamic couples which neutralize one another, thus insuring balanced action.

The action of centrifugal force on a rotatingbody is well known; in the case of a wire or rope attached at one of its ends and carrying a weight at its other end, and which is caused to rotate around its point of attachment', the action of the centrifugal force developed will be to maintain the same under tension; to what extent may be easily imagined when we consider that a weight of one ounce travelling at a peripheral speed of one thousand feet per second will produce a radial tension of about 1000 pounds, and at 1500 feet per second about one ton. It is evident, therefore, that a virtual or kinetic rigidity is thus'supplied, which may sufficiently replace the structural rigidity of the usual air propeller, and make possible a flexible aerofoil capable to function properly at suitable peripheral speeds.

The centrifugal force developed by a r0.- tating body increases in proportion to the square of the velocity; therefore a high peripheral speed is desirable in a device of this I kind. On the other hand, one of the main objects to be obtained in the construction of an aerial propeller is-the-possibility of efficient operation of the same at a compara tivelyllow angular speed; therefore, it willbe necessary to have the aerofoils rotating in a great radius. 1 I

I have, therefore, designed a propeller composed of a plurality of rotating aerofoils connected to the axle by means of cables which may be increased in length at will; so that the peripheral speed of the aerofoils may be increased without changing the speed of the engine. 1

In the patent mentioned, previously granted to me, and in a co-pending application filed by me March 15, 1921, having for title Method and apparatus for utilization of centrifugal force, Serial No. 452,586, I have described and claimed methods and apparatus for utilizationof centrifugal force by maintaining under tension flexible carriers which may also be extensible, and oneend of which is secured to a rotatable shaft.

In Figs. 26, 27. of patent application #452,586, I show a possible way of utilizing centrifugal force by attaching planes at the ends of the flexible carriers in such a way as to create a reaction against the surface of said planes during the course of their rotation causing the flexible carriers to remain in "an upwardly inclined position; namely, at a position where the lifting power due to said reaction counterbalances the action of the centrifugal force tending to cause the flexible carrier to assume a horizontal position. No means, however, are shown in said figures providing for the possibility of utilizing the centrifugal force in the composition of a force having an axial direction. The attainment of this specific purpose constitutes the main object of the present invention and calls for the employment of additional elements as willmore clearly appear later from the description. Through the application of my method a propeller can, therefore, the obtained consisting of aerofoil blades attached at the ends of flexible carriers having their free ,ends secured to a rotatable axle; and by making said flexible carriers extensible the radius of the propeller thus obtained may be increased or decreased at will. and with it the propelling power produced without changing the speed of rotation. By means of this construction it is, therefore, possible to obtain propellers having very large dimensions when in'use but adapted to occupy a very small space before expansion.

It is well known that one of the aims of modern aviation is to find a type of aeroplane which may be built to ascend and descend in a vertical direction; the solution of this problem lying principally in the application of propellers rotating in a horizontal plane and capable of producing a pulling power suflicient to lift the entire weight of the aeroplane. This result can only be obtained through the employment of propellers having a great diameter and rotated at very high tip speeds, which may be impractical on account of the bending strain on the blades of the propeller itself, and on account of the bulk and the weight of the same.

The improved type of propeller which may be constructed according to my invention is peculiarly fit for use also in connection with aeroplanes adapted for vertical travel; this being due partly to the fact that the propeller can be extended to considerable dimensions, and, therefore, high circumferential speeds be obtained through the employment of comparatively slow speed motors and partly to the fact that the propelling power is exerted through elements which are acting under tension, and therefore can be made much lighter than elements which must be subjected to bending strains.

The advantages of an aeroplane capable of vertical travel as compared with the aeroplane of the ordinary type are numerous and important, among the principal ones being the following:

therefore, the possibility of starting from or landing on buildings, squares, ships, etc., at a slow and safe speed. 2. The possibility of staying still in the air over a given point, and, therefore. to insure exactness of bombing or other offensive action, recognition and 1. No necessity of having. wide open spaces for starting or landing;-

signalling purpose and of realizing ideal conditions for the taking of photographs from the air. 3. Great stability of the apparatus, the support being all above and the weight below, and because of the gyroscopic action of the rotating planes.

Having, elected to adopt aeroform wings revolving in very large radii at low angular velocity, the efficient high-speed aeroplane engine may still be utilized as a prime mover, through the interposition of suitable reducing gear. To safeguard against disablement one or more reserve engines may be carried, to be thrown in at will, or automatically if one of the motors goes dead, but all that is not shown in the drawings be: cause I have preferred to design a helicopter that follows the usual lines of the aeroplane fuselage, with rudder and stabilizing tail plane, in order to obtain some of the volplaning possibilities of the usual aeroplane in case of engine failure.

In the construction of helicopters two concentric lifting screws are usually mounted one above the other and turning in the opposite direction, so that the machine will not spin around its axis when aloft. In the machine designed by me I prefer to assign this duty to the rudders and planes shown in the drawing, which will equally act when the helicopter should be in horizontal or vertical flight.

The methods generally proposed for pro-' pelling the helicopter are to manipulate the screws so as to upset its normal equilibrium and, therefore, obtain a forward movement; or to use an additional screw or screws for purely propulsive purposes; or to simply tilt the column that carries the horizontal screws, because the propellers, when canted from the vertical exert both a sustaining and a propelling force, and it is especially in this.

last method that I rely upon, on account of the ease with which my new form of aeroplane can be manipulated from the vertical to the horizontal plane.

In the drawings I illustrate the construction of my improved propeller andits application to aeroplanes built for horizontal and I I vertical travel, and in the same:

FlgS. 1 and 2 are diagrammatic views of the composition of centrifugal and lifting forces in my novel propelling method em-. bodying my invention; V

Fig. 3 is a side sectional view of an uplifting aerofoil rotated by flexible ropes; Fig. 4. is a view in perspective of the same;

Fig. 5 is a perspective view of three up- Fig. 9 is a detail plan sectional view of same through line 9-9 of Fig. 8;

I aeroplane embodying my invention.

Referring to the drawings, in Fig. 1 I show the diagram of the composition of centrifugal and lifting or propelling forces in the novel flexible propelling method embodying my invention. Let us assume that the flexible member B P, inclined at an angle a to the vertical and carrying a weight at F, is revolving at such an angular velocity (about the fixed point B) as to develop at P a centrifugal force C. Evidently, if the force C was the only force acting on the system, the member B P could not be in equilibrium. If .we app-1y another force f at P of such a magnitude that the resultant R, obtained by compounding it with C, will be in alignment with B F, the moment of said resultant about the fixed point B will be zero, consequently the system will be in. equilibrium.

By taking moments of the component forces about B we find cm=fn (l) equation (2) giving the complete solution of the dynamic problem.

From it if two elements of the system are assumed all the other elements will be immediately found.

In practice, the magnitude of the centrifcompound themselves in a double lifting force axially directed.

Figs. 3 and 4 show an aeroform design of lifting wing built up of aluminum partitions 20, sheathed upon their upper and lower surfaces 21,122, with the same ma-' terial, in order to provide the desired degree of strength.

23, 24, designate tubes running longitudinally to the wing and secured to the same by means of clamps 25, 26. Said two tubes are respectively bent forward at 27 and rearward at 28 at the outer end of the wing, said bends being directed towards the achacent wings of the propeller as shown in Flg. 6. Within said tubes are slidably inserted retaining cables 29, 30, each formmg a closed circuit between the hub and two ad acent wings, as will be clearly seen by referring to Figs. 6 and 11. The number of cables used is equal to the number of wings entering into the construction of the .propeller, so that in the propeller shown in Fig. 6, comprising three wings, three cables 29, 30, 31 are employed, while in the propeller the hub of which is shown in Fig. 11, comprising four wings, four cables 3232, 3333', 3434, 3535, are used. By referring to said Fig. 11 it will be seen that each cable is bent at the points 32". 33", 3t", 35" where the same are. inserted through and retained by the hub 36, the two strands of each cable thus obtained being wound spirally around said hub in a flat spiral; so that if the hub is rotated in the direction of the arrow all the cables are si multaneously unwound ofthe same quantity, while the reverse happens if the hub is rotated in the opposite direction. Means for controlling the operation of the hub for winding or unwinding the retaining cables will be described later; butassuining that the relative position of the cables and the hub be rendered stationary-it will be seen that if the propeller thus formed is rotated at considerable speed the effect of the centrifugal force exerted on the wings will be to keep the various wings under tension both radially and peripherally; and

the greater the. speed the greater the rigidity of the system. In order to create in the wing elements a tendency to move in a direction parallel to the action of the propeller, however, it is necessary to maintain the active surfaces of said wings at an angle of incidence in relation to the plane of rotation; and this is obtainedby making the are bent portions 27, 28 of the wing tubes sulliciently long and bent at the right angle so as to maintain the peripheral strands of the cables in the right position. In other words, the rearward bent portion 28 of one wing must be directed toward the forward bent portion 27' of the adjacent wing when both wings are set at the same predetermined angle of incidence. vThe action of the air against the wing surfaces will be the same for all the wings of a propeller and will constantly create a tendency in the rear part of a wing and the front partof the adjacent wing to move away from each other. This will obviously be prevented by the peripheral strand connecting said two portions of adjacent wings. and therefore the angle of incidence will be. maintained throughout. For each ,wing we'have therefore created the condition diagrammatically illustrated in Fig. 1, C representing the centrifugal force tending to cause the wings to move in a radial direction and lllltl F representing the reaction of the air strikltCTD of maintaining the retaining cables under tension at an upwardly inclined angle. A

. propeller being formed of a plurality of symmetrically arranged elements, counterbalancing each other, a system will be created such as diagrammatically illustrated in Fig. 2 where the ultimate resultant force is axially directed, same as in a propeller of ordinary construction.

In Fig. 5 I show a propeller of the type illustrated in Fig. 6 in its position of rest.

In Fig. 7 I show a biplane aerofoil which may be used in a similar manner in connection with two sets of retaining cables. The same consists of two metallic frames 37, 38 on which are stretched two panels 39, 40, preferably made of cloth such as ordinarily used for aeroplane wings, and each provided with front bent tubes 43, 44, said tubes respectively receiving retaining cables 45, 46, 47, 48. In order to better equalize the pressure of the air against the two surfaces the two frames are shown connected by two inverted arms 49, 50!, interlocking through a pin and slot connection 51. When there is excessive pressure on one of the planes the arm integral with the same will tend to incline the other plane so as to increase its angle of incidence and therefore increase the pressure on the same in order to equalize the planes.

In Figs. 8, 9 and 10 is shown a mechanism that may be used both for an aeroplane and for a helicopter type of flying machine. Referring to said drawings, 101 designates a rotatable frame motor integral with an axle 102 which is formed with a tapered portion 103. On said axle is inserted a sleeve 104 mounted on the horizontal shaft 122 pivotally mounted on an aeroplane body or fuselage 126. 120 designates a frame in which the motor is mounted fixed on shaft 122 by means of lugs 121121. Said shaft 122 may be rotated around its axis by means of a worm wheel 123 operated by worm 123, which is controlled by a hand wheel 124, so that axle 102 may be caused to assume a horizontal position or an inclined position as shown in dotted lines in Fig. 12. On axle 102 is also mounted another sleeve 105 having a tapering portion supported by the tapered portion 103 of axle 102 and becoming-integral there- 'with on account of the wedging action taking place; said sleeve 105 however is capable of axial motion on said axle so that it may be detached from close contact with tapered portion 103 and rendered loose on said axle.- The upper part of said sleeve is formed with teeth 117, 118 constantly in mesh with similar teeth provided on the lower face of a core 116 to which are fixed the flexible elements as shown in Fig. 1'1, and which is loosely mounted near the end of axle 102. Said core 116 is locked against axial motion by two blades or flanges 106, 106' forming a reel or housing for the flexible elements. tegral to axle 102' by means of set screw 107 and key 108; while flange 106' is secured to the same by means of bolts 109 and is provided with a collar portion 108' which fits looosely around the top portion of sleeve 105 and the lower portion of core 116.

For the operation and control of the flexible elements in the manner which will be hereinafter described means are provided for causing the slight axial motion of sleeve 105 necessary to attach or detach the same through intimate contact with tapered portion 103 of axle 102, or for exerting'a braking action on the same. For this purpose Flange 106 is rendered insleeve 105 is formed intergral with a flange 119 having its lower surface inclined downwardly. Around the lower portion of sleeve 105 is mounted a collapsible collar formed stood that if said screw 141 is operated soas to close the collar the action of the same against the inclined surface of flange 119 will be to force sleeve 105 in an axial direction out of contact with tapered portion 103, while if the two collar portions are further drawn together the same will exert a brake band action against the lower part of sleeve said action being adjustable at will.

In the first case, that is when sleeve 105 is detached from tapered portion 103 the sleeve becomes loose on the axle 102, and may, therefore, rotate independently of said axle, allowing the cables to extend under the action of centrifugal force. By again opening the two collar members 137--137 if axle 102 is in a Vertical posltion, sleeve 105 will, by the action of its own weight fall back into contact with tapered portlon 103; and in this position, therefore, will agam assume the same speed as axle 102, and will, therefore, maintain the cables in their new extended position.

If axle 102, however, should be inclined or horizontal, as shown for instance in Fig. 12, the action of its weight might not be suflicient to cause sleeve 105 to fall back into contact with tapered portion 103. have, therefore, added a system of four spring operated fingers 145, pivotally mounted on collar members 137137 and exerting pressure against a thrust ball-bearlng 146 mounted on flange 119. The pressure exerted by said fingers will, therefore, cause sleeve 105 to move inwardly into contact with tapered portion 103 when collar members 137-137 resume their open position. In order to rewind the cables on the reel, handwheel 144 is operated like in the previous case to close collar members 137137; this will first cause sleeve 105 to become detached from tapered portion 103 and then as handwheel 144 is further rotated collar members 137-137 will gradually exert a braking action against said sleeve causing the same to assume a speed lower than the speed of axle 102 and of reel 106106 mounted thereon. The four double strand cables held between the reel flanges, therefore, which are guided by rollers 50, as shown in Fig. 11 will be caused to wind again around core 116 by the reel itself; since the reel, as stated, rotates at a speed which is higher than the speed of the core, the core being integral with sleeve 105; the cables will thus be gradually retracted; and the radius of action of the propeller will become smaller until through the operation of handwheel 144 sleeve 105 is again caused to resume its intimate contact with tapered portion 103.

The device as described is suitable for use in an aeroplane of the ordinary type without the necessity of using additional controlling devices; when the same is used in connection with a helicopter, however, it is necessary that the supporting planes 147, 148 be pivotally mounted so as to be inclinable at will. In the drawings the same are shown pivotally mounted on the extensions 149, 150 of shaft 122, and respectively controlled by hand levers 151, 152. Said levers may be provided with a tooth 153, 154, or with any other suitable means and c'ausedto engage geared segments 155, 156, respectivel supported b5 brackets 157, 158, at any esired angle. uring the vertical ascent' and descent of the helicopter, these two planes may be caused to assume a vertical or nearly "ertic'al position, so as to diminish the resistance of the air; but it is advisable to have one plane arranged at a different inclination from the other in order to create a couple antagonistic to the tendency of the machine to rotate on its axis, which mi ht be due to the action of the propeller, hen the machine should remain still in the air the action of this couple would of course disappear and spinning of the apparatus might take place. In this case a small side propeller could be used exerting action antagonistic to said spinning, but this case is so rare that it has not been deemed necessary to illustrate this application in the drawings.

In Fig. 10 a helicopter is shown in which the device illustrated in Figs. 8 and 9 is used. In the same the different inclination of the supporting planes is shown to counterbalance the spinning action of the propeller,

said planesbeinv arranged'so as to insure the possibility of volplaning in case the engine or engines should go dead. In the same a conical cap 159 is shown mounted at'the end of the axle in order to diminish the resistance of the air. The engine as shown in Fig. 8 is integral with the axle; but in case of propellers of large radius of action and relatively low angular speed, some suitable intermediate reducing gear may be provided between theengine and the propeller axle. Such a modification may be easily understood without the necessity of illustration.

Devices built on similar principles may also be used for different purposes in stationary installations, the wings, for instance, may be used for ventilating stadiums and public spaces.

From the foregoing it is seen that I provide an entirely new method of utilizing centrifugal force and an entirely novel construction of propeller based on the same. The drawings are intended for purposes of illustration onl and it is understood that many details 0 construction may be modified to a considerable extent without departing from the spirit of my invention. I, therefore, reserve myself the right to carry my invention into practice in such ways and forms of construction as may be deemed advisable in order to satisfy different requirements, and as may enter, fairly, into the scope of the appended claims.

I claim:

1. The combination in a device for aerial propulsion, of a series of plane elements, means for revolving the same around a common shaft, carriers for said planes exten sibly connected to the shaft, extensible connecting links between adjacent planes attached to the extensible carriers, extensions from the planes through which the extensible carriers and connecting links pass, so

arranged that the tension on said carriers caused by centrifugal force, will serve as a means in co-operation with the links to keep the planes at the angle of incidence to their plane of travel that they will naturally assume due to their construction.

2. In a device of the class described and in combination with a plurality of plane elements and an axle, flexible means connecting two adjacent plane elements to said axle and also connecting the outer ends of said two plane elements to each other so as to in combination with aplurality of plane 3 .said flexible elements.

5. In a device of the class described, and in combination with aplurality of plane elements, an axle, and a plurality of flexible elements connecting said plane elements to said axle and to each other, means causing the simultaneous extension or retraction of said flexible elements, and means controlling the operation of said extending and retracting means. 6. In a device of the class described, the

'combination of a plurality of plane elements lwjvith an axle, a pluralitf of flexible elements connecting said plane e ements to each other and to the axle, means for causing the simultaneous extension or retraction of said planes of an equal amount and means for controlling the operation of-said extending and retracting means at any suitable'speed.

7. In a device of the class described, the combination, with a plurality of plane elements revolving around an axis, of means for maintaining said elements at a given angle of incidence, said means comprismg peripheral connections between the outer ends of said elements, said connections being so arranged, that deviation of any one element from its angle of incidence is checked by the others.

8. In a device of the class described, the combination, with a plurality of plane elements revolving around an axis, and flexible carriers therefor, of peripheral connections between the outer endsof said elements, integral with, aiid cooperating with said carriers, to maintain said elements at a given angle of incidence.

' MARIO SCHIESAIEI. 

